1. Field of the Invention
This invention relates generally to inductors, and, more particularly, to a design of inductors for high power, radio frequency applications having an optimal combination of self resonant frequency and quality factor while minimizing component volume.
2. Discussion
Inductors are typically used as devices for storing energy in electrical circuits. An inductor has many uses in the field of electronics. In particular, inductors find applications in filters, tuned circuits, energy storage devices, and electrical measuring devices. Inductors are often used in radio frequency (RF), high power applications as well.
Because many RF, high power applications require high power processing densities, it is advantageous to be able to provide inductors which require a minimum of space, weight, and cost for production. These requirements have spawned a class of printed inductors which desirably have high inductances and can handle relatively high currents.
Such varied inductors preferably provide an optimal combination of self resonant frequency (SRF) and quality factor (Q) while minimizing component volume.
Present inductors are embodied as spiral inductors, which are flat inductors printed on a single substrate layer. Spiral inductors, however, exhibit low inductance and high resistance, resulting in a low Q which is unacceptable for high power applications. Further, the spiral inductor yields a relatively small inductor value (L), which is not commensurate with the large surface area that the inductor requires.
Thus, it is an object of the present invention to provide a high power inductor which has a high inductance value L and high current capacities.
It is a further object of this invention to provide an inductor having a desirable combination of SRF and quality factor Q, but which requires minimum component volume.
It is yet a further object of the present invention to provide an inductor which improves the efficiency, decreases the size, and increases the power density of very high frequency (VHF) power supplies and RF circuits in general.
It is yet a further object of the present invention to provide a pyramid, vertical solenoid inductor having minimal inner-edge spacing between adjacent traces, thereby resulting in a reduction of the component surface area.
It is a further object of the present invention to provide a pyramid, vertical solenoid inductor exhibiting less proximity effect than typical spiral structures.
It is yet a further object of the present invention to provide a staggered, vertical, solenoid inductor which eliminates conductor overlap between adjacent turns of the inductor in order to minimize parasitic capacitance and maximize component SRF.
It is yet a further object of the present invention to provide a staggered vertical solenoid inductor of sufficiently reduced height without affecting the SRF performance characteristic.
In accordance with the teachings of the present invention, this invention is directed to vertical solenoid inductors which includes a plurality of adjacent layers. Each layer is arranged to minimize overlap with adjacent layers in order to minimize electrical interaction between each layer. Each layer is then electrically connected by a via.
Additional objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in connection with the accompanying drawings.